<P>没有你要的，找了个函数，大概有点关系，看看有没帮助</P><P>'‖=================================================
'‖功能：多边形联合形成新的多边形
'‖参数：pFromPolygon 原多边形
'‖     pToPolygon 加入的多边形
'‖输出：构成的多边形
'‖=================================================
Public Function UnionPolygon(ByVal pFromPolygon As IPolygon, ByVal pToPolygon As IPolygon) As IPolygon
  Dim pTopoOperator As ITopologicalOperator
  
  On Error GoTo ErrLabel
  
  Set UnionPolygon = Nothing
  If pToPolygon Is Nothing Then
    Set UnionPolygon = pFromPolygon
    Set pTopoOperator = UnionPolygon
    pTopoOperator.Simplify
    Exit Function
  ElseIf pToPolygon.IsEmpty Then
    Set UnionPolygon = pFromPolygon
    Set pTopoOperator = UnionPolygon
    pTopoOperator.Simplify
    Exit Function
  End If
  If pFromPolygon Is Nothing Then
    Set UnionPolygon = pToPolygon
    Set pTopoOperator = UnionPolygon
    pTopoOperator.Simplify
    Exit Function
  ElseIf pFromPolygon.IsEmpty Then
    Set UnionPolygon = pToPolygon
    Set pTopoOperator = UnionPolygon
    pTopoOperator.Simplify
    Exit Function
  End If
  
  Set pTopoOperator = pFromPolygon
  pTopoOperator.Simplify
  Set pTopoOperator = pToPolygon
  pTopoOperator.Simplify
  Set UnionPolygon = pTopoOperator.Union(pFromPolygon)
  Set pTopoOperator = UnionPolygon
  pTopoOperator.Simplify
ErrLabel:
    
End Function</P>